alternator upgrade

[zeehond]

Has anyone experience of fitting a high output alternator, say 120 + amp to a Perkins M60. It currently has a Lucas A127 which is not adequate for charging the 500 a/h battery bank of our Warrior 40 S/Y.
We are looking for a Right Hand alternator with isolated earth.
All advice welcomed.

 

[charles_reed]

Speak with Adverc:-

Adverc Battery Management Systems

Tel: 01902 380494
Email: techsales@adverc.co.uk

Even if you're not intending to buy one of their external controllers.

 

[[2574]]

No directly relevant experience though I have fitted a 120A alternator to our Yanmar (also 500+AH battery bank). These people were very helpful: http://www.electromaax.com/ and critically by fitting a serpentine belt kit I didn't have to fit a double vee pulley to the crankshaft; that in itself somewhat diminishes the difficulty of upgrading.

 

[pvb]

Robih raises a good point. Single V-belt drive is only really suitable for 12v alternators up to 100A - above that you really need a double V-belt or need to change to a flat poly-V belt system.

Frankly, with a 500Ah bank, a good 90A or 100A alternator would be adequate, unless you have AGM batteries (which accept higher charge rates). My old boat had a 90A Prestolite alternator with an Adverc regulator, charging a 660Ah bank of "sealed" batteries. It all worked well for years and I rarely saw more than 70A charge rate. Prestolite alternators tend to have a good output curve, with decent output at lower revs, so are ideal for boat use.

 

[Chris_Robb]

Robih raises a good point. Single V-belt drive is only really suitable for 12v alternators up to 100A - above that you really need a double V-belt or need to change to a flat poly-V belt system.

Frankly, with a 500Ah bank, a good 90A or 100A alternator would be adequate, unless you have AGM batteries (which accept higher charge rates). My old boat had a 90A Prestolite alternator with an Adverc regulator, charging a 660Ah bank of "sealed" batteries. It all worked well for years and I rarely saw more than 70A charge rate. Prestolite alternators tend to have a good output curve, with decent output at lower revs, so are ideal for boat use.

Plus 1 for Adverc. I bought a Prestolite 110a/h from them; it was already modified with a field wire for an alternator regulator and will work with either theirs or in may case I already had a Sterling one. The good thing about the 110 a/h prestolite is that it is a fully ventilated frame (and is the base for the Balmar set up) so should cool better.

They provide a 13mm pulley to allow an uprated belt to be used (fine even if your other pulleys are only 9mm). Needless to say, in the first season, I used a 9mm belt and filled the boat with black smoke from the belt slipping when the batteries were low! A change to 13mm cured this - no black dust around the alternator any more. Belts from Bearing Boys - V good value at this site
http://www.bearingboys.co.uk/V___Wedge_Belts-1025-c?gclid=COiezsWD38ECFSuWtAod2DQAVw.

One word of warning though, the pulley size diameter was marginally smaller, so now the rev counter over reads! I don't know if they will get a pulley size to match yours.

 

[neil1967]

I uprated to a 120A alternator on my Perkins 4108. I don't know if it was slightly out of alignment (I had to adapt the mounting) or the power, but I had excessive amounts of black dust (even with 1/2" width pulleys and belts from bearing boys. I ended up replacing it with a 90A alternator from www.startermotor-alternator.co.uk, who were also happy to solder in wires to the brushes so that I could then use an external alternator controller - I would recommend them. I have a 390 AH domestic bank. Although it has not been severely tested, all appears well, and a substantial improvement on the 120A alternator.

Neil